1. Technical Field
The present invention relates to a substrate strip, and more particularly, to a substrate strip in which units having semiconductor chips mounted thereon are disposed in at least one row.
2. Description of the Related Art
Generally, several tens to several hundreds of chips may be formed per one wafer. However, the chip itself may not receive electricity supplied from the outside to transmit and receive an electric signal. In addition, since the chip includes fine circuits, it is easily damaged due to external impact.
Therefore, a packaging technology of performing electrical connection to the chips and protecting the chips from the external impact has been gradually developed.
Recently, demands for high integration of a semiconductor device, an increase in memory capacity, multi-functionalization, high density mounting, and the like, have increased. In order to satisfy these demands, a bonding structure is changed from a bonding structure using wire bonding to a bonding structure using a flip chip bump. In a structure performing a high-end level function among these structures, a bump is formed in a substrate strip state in order to improve an assembly yield.
Here, the substrate strip means that substrate units having semiconductor chips mounted thereon are disposed and connected to each other in at least one row and includes the substrate units on which the semiconductor chips are mounted and a dummy region formed in the vicinity of the substrate units.
This substrate strip has been mainly utilized in a packaging process of a semiconductor device.
The package process of a semiconductor device includes a process of mounting a semiconductor chip on a substrate unit of the substrate strip, a process of molding the substrate strip using a molding material, and a process of cutting the substrate strip into each substrate unit, and the like.
In the process of molding the substrate strip according to the related art, the substrate unit is covered by a molding clamp, and the molding material is injected into the molding clamp to perform the molding.
In this case, deformation such as warpage, torsion, and the like, occurs in the substrate strip due to thermal stress and moisture absorption generated at the time of manufacturing the substrate strip, and a prominence-depression is formed at the time of applying a solder resist. Close adhesion force between the substrate strip and the molding clamp is decreased due to the deformation of the substrate strip and the prominence-depression of the solder resist, the molding material is leaked through a gap between the substrate strip and the molding clamp in a molding process, such that flat molding is not performed, and problems such as a molding defect that the molding material is leaked to the dummy region, a molding apparatus fault, and the like, occur.